<template>
  <header class="header">
    <h1>todos</h1>
    <input id="toggle-all" class="toggle-all" type="checkbox" >
    <label for="toggle-all"></label>
    <input
      class="new-todo"
      placeholder="输入任务名称-回车确认"
      autofocus
      v-model.trim="taskname"
      @keydown.enter="add"
    />
  </header>
</template>

<script>
export default {
 data(){
     return{
         taskname:''
     }
 },
 methods: {
     add(){
         if(this.taskname.length==0) return alert('请输入任务名称!');
         this.$emit('addTask',this.taskname)
         this.taskname=''
     }
 }
}
</script>